On the Road

Trucking down the glass highway

January 9, 2012

Glass highway? Does that have something to do with electronic dashboards, as in the Glass Cockpit concept in modern aircraft? Nope, we're talking about roadways made of glass. But you're not far off on the electronic angle.

Paved road surfaces have been around for thousands of years, but the basic construction technique and the materials used haven't changed much in the last 100 years.

The ancient Romans are credited with building the first paved roads using tightly fitted blocks of stone. Some of those roads, the Appian Way in Rome for example, have survived more than 2,000 years. Roman city streets, with their curbstones and elevated sidewalks, became the basis for today's street designs.

According to www.curbstone.com, The first recorded "paved" road in America dates back to 1625, and is said to be in Permaquid, Maine. It is now called Colonial Pemaquid Drive. In 1795, the Philadelphia to Lancaster turnpike became the first "engineered" road in America -- and it was a toll road.

In the early 1800s, a pair of Scots, Thomas Telford and John Loudon McAdam pioneered road building techniques that are still used today. using an underlay of stones of various sizes laid in symmetrical, tight patterns and covered with compacted surface of much smaller stones and sand. That technique became what we today call a macadam road. Telford gets credit for raising the foundation of the road in the center so water could drain off to the sides, making them less susceptible to puddles and rutting.

The first macadam surface in the United States was laid in 1823 on the Boonsborough Turnpike Road between Hagerstown and Boonsboro, Maryland.

Road builders enhanced the macadam technique using what was the forerunner of cement as a surface. Spraying stone dust with water improved its binding ability, creating a more durable surface. Later, a bitumen-based tar replaced water as the binder, becoming the forerunner of modern asphalt. That technique was called tarmacadam. The word was later shortened to the now familiar "tarmac." In 1854, The Champs-Elysee in Paris became first tarmac road ever built.

The first American uses of road asphalt were in Battery Park and on Fifth Avenue in New York City in 1872, and on Pennsylvania Avenue, Washington D.C., in 1877. On July 4th, 1909, Detroit's Woodward Avenue between 6 Mile and 7 Mile Roads became the nation's first mile of concrete pavement.

Today there are more than 2.7 million miles of paved roads in the U.S. At $1,000 a ton for liquid asphalt, imagine what it could cost to repave all those roads?

If the price of oil continues to rise, or if the stuff becomes precious enough as we come closer to exhausting the supply, we'll be scrambling for new materials for road construction. So, why not glass?

It's easy and inexpensive to manufacture, the raw materials are in abundant supply, and suitably engineered glass roads could also generate enough electricity to power every town and city in the country.

Sound far fetched? Check out the video below and then tell me its impossible.

Scott Brusaw, the co-originator of the Glass Highway concept already has a working prototype, and will soon begin installing test patches in parking lots.

There's still work to be done, but this idea is rife with potential.

Highway construction techniques haven't changed much in 100 years; the time might be right for a truly revolutionary concept. Check out the video before you dismiss the idea.